1. EPRS1 Controls the TGF-β Signaling Pathway via Interaction with TβRI in Hepatic Stellate Cell
- Author
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Yoon, Ina, Song, Ji Ae, Suh, Ji Hun, Kim, Sulhee, Son, Jonghyeon, Kim, Jong Hyun, Jang, Song Yee, Hwang, Kwang Yeon, Kim, Myung Hee, and Kim, Sunghoon
- Subjects
Biochemistry and Cell Biology ,Biological Sciences ,2.1 Biological and endogenous factors ,Aetiology ,1.1 Normal biological development and functioning ,Underpinning research ,Humans ,Hepatic Stellate Cells ,Receptor ,Transforming Growth Factor-beta Type I ,Receptors ,Transforming Growth Factor beta ,Transforming Growth Factor beta ,Fibrosis ,Signal Transduction ,glutamyl-prolyl-tRNA synthetase 1 ,transforming growth factor receptors ,halofuginone ,Medical and Health Sciences ,Developmental Biology ,Biological sciences ,Biomedical and clinical sciences ,Health sciences - Abstract
Glutamyl-prolyl-tRNA synthetase 1 (EPRS1) is known to associated with fibrosis through its catalytic activity to produce prolyl-tRNA. Although its catalytic inhibitor halofuginone (HF) has been known to inhibit the TGF-β pathway as well as to reduce prolyl-tRNA production for the control of fibrosis, the underlying mechanism how EPRS1 regulates the TGF-β pathway was not fully understood. Here, we show a noncatalytic function of EPRS1 in controlling the TGF-β pathway and hepatic stellate cell activation via its interaction with TGF-β receptor I (TβRI). Upon stimulation with TGF-β, EPRS1 is phosphorylated by TGF-β-activated kinase 1 (TAK1), leading to its dissociation from the multi-tRNA synthetase complex and subsequent binding with TβRI. This interaction increases the association of TβRI with SMAD2/3 while decreases that of TβRI with SMAD7. Accordingly, EPRS1 stabilizes TβRI by preventing the ubiquitin-mediated degradation of TβRI. HF disrupts the interaction between EPRS1 and TβRI, and reduces TβRI protein levels, leading to inhibition of the TGF-β pathway. In conclusion, this work suggests the novel function of EPRS1 involved in the development of fibrosis by regulating the TGF-β pathway and the antifibrotic effects of HF by controlling both of EPRS1 functions.
- Published
- 2023